Newly built single-family house - gas or air heat pump + photovoltaics + storage?

I’m bringing the thread back up again. Out of ignorance, we didn’t get good advice when building our house and are currently constructing an Energy Saving Ordinance house with gas + solar thermal :( The house will have a controlled residential ventilation system with heat recovery and a small fireplace. Since construction is already underway, we no longer have the opportunity for funding. The step to KFW 55 was actually not far away, but we didn’t know that at the time. Unfortunately, we really slept on that.

For several weeks now, the topic of gas has really been giving us a headache. So thanks for the thread! Even though I still couldn't make a decision after reading it.

We would prefer to go for a geothermal heat pump (our neighbor has had one for 14 years and raves about it). We have gotten quotes, and without funding, we unfortunately cannot afford the geothermal heat pump. We have been calculating back and forth for days, but the geothermal heat pump would cost us 30,000 euros more (the saved costs for the gas condensing boiler and solar thermal are already taken into account). So, a (in my opinion) really big chunk. An air-water heat pump would cost us 12,000 euros more. That is also a lot, but we could somehow manage it over the next few years. What arguments have we already gathered (also thanks to this thread)?

Gas + mature technology + quiet + we don’t need expertise + heats reliably at all outdoor temperatures +- you could book an eco gas tariff that invests in CO2 offset measures - fossil - price fluctuations - only in combination with solar thermal

Air-water heat pump + CO2 neutral + combinable with own photovoltaics + no solar thermal - might disturb our neighbor (his bedroom would be 8m from the location of the air-water heat pump) - you have to understand it/learn a lot - apparently short lifespan (we read 10 - 20 years online) - investment without funding probably won’t pay off for us

I have already tried to find out how future-proof gas is and whether there will eventually be alternatives to gas that can be fed into the existing networks. Currently, every second household in Germany heats with gas. But the results so far have been rather sobering.

For climate protection reasons, we would take the air-water heat pump as a financial compromise. But we are afraid it will only cause us problems (with the neighbors, with our technical ignorance, and with our wallet). Maybe someone here has a good tip or food for thought for us that will help with the decision :)

Your gas boiler can also process hydrogen. I would opt for photovoltaics instead of solar thermal. Electricity is also becoming more expensive. At the time when you need the most energy, you have the least (at night, in winter...). Since your budget is already tight, take the gas boiler.

I would say take an air-to-water heat pump. Or a brine-to-water heat pump with a trench collector.

How many of your neighbors have an air-to-water heat pump?

Ignorance is not well advised and we are currently building an energy-saving regulation house with gas + solar thermal. The house is getting a controlled residential ventilation system with heat recovery and a small fireplace.

Then you haven’t been around here enough!
Did you originally plan the combination with underfloor heating on the ground floor and radiators on the upper floor?

We have been calculating back and forth for days but the geothermal heat pump would cost us 30,000 euros more (the saved costs for the gas condensing boiler and solar thermal are already taken into account).

What does the detailed cost breakdown look like?

I would say take an air-to-water heat pump. Or a brine-to-water heat pump with a trench collector.

How many of your neighbors have an air-to-water heat pump?

We have already read a lot about a brine-to-water heat pump with a trench collector, but we cannot reasonably apply this interesting technology due to the condition of our property (many old trees and boundary development with sheds).

Nobody in our neighborhood has an air-to-water heat pump. We are building new on a rear lot in the old part of a small town. Our neighbor right next to us has a brine-to-water heat pump with deep drilling, our other neighbor a bit further away also. The rest have gas or oil.

Then you haven’t been here enough!
Do you have the originally planned combination with underfloor heating on the ground floor and radiators upstairs? :rolleyes:

What does the detailed cost breakdown look like?

We have underfloor heating upstairs and downstairs. We have not received a detailed cost breakdown or exact information about the technology, only a flat rate price for the heat pump including all installations for the heating.

An Arotherm Plus from Vaillant was offered as an air-to-water heat pump.

Gas? Air heat pump + photovoltaic + power storage? Ground-source heat pump? Or something completely different?

We asked ourselves the same question for our house construction in 2022 and initially decided on gas, as the heating system can later be (easily?) converted to hydrogen.
Regarding photovoltaic, we will make preparations for a later date when storage systems have become more affordable.